Aberdeen were awarded a penalty after 52 minutes when referee Calum Murray ruled that Steven Smith was fouled in the box by Gary McDonald. Chris Maguire stepped up for the spot-kick but was denied by a great save from Tomas Cerny.
Hamilton grabbed the opener after 64 minutes when Dougie Imrie - on his 50th appearance - raced onto a pass from Nigel Hasselbaink before keeping his cool and slotting past goalkeeper Jamie Langfield.
Langfield was then forced out of the action and replaced by Mark Howard just two minutes later after he was caught on the face by the boot of team-mate Zander Diamond.
Aberdeen replaced Scott Vernon with Blackman after 73 minutes and he grabbed the equaliser just two minutes later. Maguire supplied the pass, squaring across the face of goal for the on-loan Blackburn forward to rifle home at the far post.
Blackman was then denied his second when his shot bounced off Cerny and crashed off the upright as the match ended all-square.
Source: PA
Source: PA